This post was updated on October 9, 2012
(MoneyWatch) Not long ago I told you a few strategies for performing a reverse e-mail lookup. You can search Facebook, Google, or photo search engines, for example, to locate someone who sent you an e-mail. It's hit or miss, to be sure, but you can sometimes score a direct hit.
Performing a reverse phone search is theoretically much more straightforward -- you enter a phone number in a Web page and learn the person's name and address.
Unfortunately, reverse cell phone lookups remains one of the few kinds of online searches that it's almost impossible to get for free. There are just a few, and what works today for me might not work for you next week.
That said, the best way to look up someone based on a phone number right now is Facebook. That shouldn't surprise anyone based on the service's spotty privacy record, but in this case it certainly works to your advantage if you're looking up a phone number. Just open Facebook and enter a phone number in the search box at the top of the screen, then press Enter. If that individual has associated their phone number with their Facebook profile, they will appear as the top search result, regardless of their privacy settings and even if you are not friends.
That's great, but what if that person hasn't linked their phone number to their profile, or they don't use Facebook at all? Then it's time to try your luck with a dedicated reverse phone lookup site. When I first wrote this post, I had found a reverse phone lookup site that gave excellent results with both landline and cell phone numbers. Since then, readers have run into problems with the site, and so have I.
In principle, the simply named Phone Lookup is like the Google of phone lookup Web pages -- just enter the phone number you want to reverse engineer and click Lookup.
In my experience, at times, this site is quite good at identifying the personal information of whoever is behind the phone number you enter. Often, though, it will simply announce that the information is unpublished. The site does offer to deliver names and other personal data about the owner of the phone number. I haven't paid the $4.95 fee for a one-time report, and I recommend that you avoid handing over a credit card to Phone Detective as well.
If you happen to find a reliable way to perform a reverse cell phone lookup, please pass on your scoop in the comments.